Zakaria Amara testing out a detonator in his basement

n the spring of 2006, police spotted and overheard Zakaria Amara many times talking about his attempts to construct prototype detonators. Through trial and error, he settled on some cellphone-triggered circuitry, which could be used to set off a bomb from a remote location.

He filmed himself testing out the device in his basement, setting off sparks that burned his carpet.